Your form looks good, the only thing I'd recommend is ditching the shoes entirely or getting a pair of Converse/Vans with flat, non-squishy soles for the sake of stability throughout the lift and your proximity to/connection with the ground.
If you're looking to get stronger before the meet, I'd say that gaining a good 25-30 pounds (how tall are you and how much do you weigh?) and getting on a strength program yesterday would be a fantastic place to start. Important exercises that got me from your strength level to mine included eating and practicing the deadlift extensively (I was never one to do many assistance or supplemental exercises), so something like the Russian Bear Program might appeal to you. I have never tried it, but I have gone through extensive weight-gaining cycles in the past, back when my stomach could handle it, and I found quick and lasting success.
Remember also that increases in skill as well as muscle mass translate to increases in strength, so frequency might hold something for you if you're struggling with the idea of or don't want to gain weight. Newer lifters often improve rapidly when they finally figure out how to be efficient in their movements, at least from a muscle-recruiting standpoint. Getting stronger will require you to learn to use more of your existing force production abilities, improvements in which are generally derived from skill and frequency-based training (PTTP, a program calling for 5x/week Deadlift and Overhead Press, is the program I'm currently following).
Let us know how the meet goes! Best of luck to you.